高强度聚焦超声消融活体心肌的实验研究  

In vivo experimental study on myocardium ablation with high-intensity focused ultrasound

作　　者：郑敏娟[1] 周晓东[1] 王磊[1] 张海滨[1] 贺建国[1] 

机构地区：[1]第四军医大学西京医院超声科,西安710032

出　　处：《中华超声影像学杂志》2007年第2期159-162,共4页Chinese Journal of Ultrasonography

基　　金：国家自然科学基金项目（30170265）

摘　　要：目的探讨高强度聚焦超声（HIFU）技术消融活体心肌的可行性。方法以4种HIFU能量在超声实时监测下消融开胸犬室壁心肌，比较消融前后靶区组织多普勒频谱、二尖瓣口血流频谱（E、A峰峰值速度）、射血分数（EF）、心肌酶（AST、LDH、CK）及肌钙蛋白T（CTnT）含量。消融结束后取心脏逐层解剖，染色确定消融范围并测量体积。光镜及电镜观察组织显微结构和细胞超微结构变化。结果①消融后靶区组织多普勒频谱即刻降低（P〈0．05）；EF值及E／A差异无统计学意义（P〉0．05）。②心肌酶及CTnT含量有不同程度上升（P〈0．05）。③所设声能量条件下消融体积在（22．1±3．4）mm^3～（1239．2±22．9）mm^3之间。光镜观察所有剂量组消融区均发生不可逆损伤。电镜下见消融区心肌结构出现不可逆损伤表现，周边仅表现为轻度变性，变性肌丝与消融区坏死肌丝交界清楚可辨。结论HIFU技术可以实现活体动物心肌消融，消融范围可控，在心脏消融方面可能有潜在应用价值。Objective To evaluate the feasibility of high-intensity focused ultrasound（HIFU） ablation on beating hearts. Methods Open-chest models of healthy dogs were underwent myocardium ablation with HIFU in 4 different dosage. The Doppler tissue imaging（DTI） velocity tracing, blood flow spectrum of mitral orifice, ejection fraction before and after ablation were recorded for comparison. Myocardium enzyme （AST, LDH, CK） and cardiac troponin T（CTnT） were detected. Pathologic exams were also done （ included TTC , HE stain , light and electron microscope ） for finding microstructure changes . Results ①Peak velocity of isovolumetric contraction wave（IVC）, systolic S wave, diastolic E and A wave descended immediately（ P 〈 0.05） ; but there were no change in ejection fraction and E/A （ P 〉 0. 05 ）. ② The myocardium enzyme（AST, LDH, CK） and CTnT content in blood increased after ablation（ P 〈0.05）. ③ The ablation volume varied from （22.1± 3.4） mm^3 to （1239.2 ±22.9） mm^3 with these HIFU dosage. Evident inreversible damage were observed in both light and electron microscope exam in all dosage group, and lesion area periphery just appeared reversible degeneration. Sharp border between necrosis myofilament and degenerated myofilament were shown. Conclusions HIFU is effective to obtain controllable ablation in vivo myocardial tissue, HIFU technique may has potential usage in heart ablation.

关 键 词：高强度聚焦超声 心肌 狗 

分 类 号：R686[医药卫生—骨科学]